This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. 20 years and it has been the swallowing evaluation tool in over 60 peer-reviewed publications. However, amazingly scant data exists on normal swallowing as assessed endoscopically. Our long-range objectives are to obtain extensive normative data on swallowing as assessed endoscopically and to obtain comprehensive data on the inter- and intra-rater reliability of the endoscopic swallowing measures we have chosen. Our long-range objectives are to obtain extensive normative data on swallowing as assessed endoscopically and to obtain comprehensive data on the inter- and intra-rater reliability of the endoscopic swallowing measures we have chosen. However, for this R03 grant application, there are two specific aims that will obtain preliminary/pilot data towards our long-range objectives. Specific Aim One of this grant requires four separate experiments to determine the effects of seven different factors/issues on endoscopic swallowing measurements. Specific Aim Two will determine the inter- and intra-rater reliability of the four endoscopic measurements of swallowing chosen on 20% of the data stratified to represent various ages and bolus types. Intra-rater reliability will be assessed as a function of short- and long-term repeat ratings. Inter-rater reliability will be assessed as a function of three levels of clinician FEES experience (i.e., beginning, intermediate, and advanced) across nine independent raters without pre-training.